1. Field of the Invention
The present invention relates to devices for monitoring the temperature of hot gases and, in particular, to such devices which are useful in shaft furnaces such as blast furnaces.
2. Description of the Prior Art
In various industrial processes, it is necessary to monitor temperatures at one or more positions in a hot gaseous medium. In a blast furnace, for example, it is known that useful adjustments in the iron making process may be effected based upon temperature measurements which may be taken within the furnace stack. Since, however, temperatures in blast furnace stacks may range up to about 1200.degree. F., serious maintenance problems have often been associated with probes heretofore in use for this purpose. Furthermore, it has been found that the precision or accuracy of the gas temperature measurements obtained with some probes heretofore known may be adversely affected by the tendency of such probes to thermally deform so that measurements are not always taken at the same positions. It is believed that a certain degree of imprecision or inaccuracy may also result from the tendency of such probes to be subject to substantial thermal fluctuations in their interior thermocouple lead housing sections. It is, therefore, an object of the present invention to provide a gas temperature monitoring probe which avoids the above described disadvantages which have been associated with certain probes heretofore known in the art.